Exploring Metabolic\nAberrations after Intracerebral\nHemorrhage In Vivo with Deuterium Metabolic Spectroscopy Imaging

Aberrations in metabolism after intracerebral hemorrhage\n(ICH),\nparticularly lactate metabolism, play a crucial role in the pathophysiology\nand patient outcome. To date, the evaluation of metabolism relies\nheavily on invasive methods such as microdialysis, restricting a comprehensive\nunderstanding of the metabolic mechanisms associated with ICH. This\nstudy proposes a noninvasive metabolic imaging method based on <sup>2</sup>H magnetic resonance spectroscopy and imaging (<sup>2</sup>H-MRS/MRSI) to detect metabolic changes after ICH in vivo. To overcome\nthe low-sensitivity limitation of <sup>2</sup>H, we designed a new <sup>1</sup>H–<sup>2</sup>H double-resonance coil with <sup>2</sup>H-channel active detuning and proposed chemical shift imaging based\non the balanced steady-state free precession method (CSI-bSSFP). Compared\nwith the volume coil, the signal-to-noise ratio (SNR) of the new coil\nwas increased by 4.5 times. In addition, the SNR of CSI-bSSFP was\n1.5 times higher than that of conventional CSI. These two technologies\nwere applied to measure lactate metabolic flux at different phases\nof ICH. The results show a higher lactate concentration in ICH rats\nthan in control rats, which is in line with the increased expression\nof lactate dehydrogenase measured via immunohistochemistry staining\n(AUC<sub>Lac_area/Glc_area</sub>: control, 0.08 ± 0.02 vs ICH-3d,\n0.39 ± 0.05 vs ICH-7d, 0.18 ± 0.02, <i>P</i> <\n0.01; H-score: control, 126.4 ± 5.03 vs ICH-3d, 168.4 ±\n5.71 vs ICH-7d,133.6 ± 7.70, <i>P</i> < 0.05). A\nhigher lactate signal also appeared near the ICH region than in normal\nbrain tissue. In conclusion, <sup>2</sup>H-MRS/MRSI shows potential\nas a useful method for in vivo metabolic imaging and noninvasive assessment\nof ICH.